Anticipated Impact on Veteran's Healthcare: The findings of this study have the potential to improve the quality of clinical care provided to Veteran patients with obstructive sleep apnea who are prescribed CPAP. Project Background: The gold-standard treatment for patients with Obstructive Sleep Apnea syndrome (OSA) is continuous positive airway pressure (CPAP) therapy. When worn during sleep at the prescribed pressure level, CPAP therapy abolishes apnea and hypopneas, thereby normalizing sleep and breathing. CPAP therapy is a complex treatment regimen and poor CPAP adherence is well-documented. One key aspect of providing adequate chronic illness care is having a valid measure of treatment efficacy that both patients and providers can use to guide management decisions. While the CPAP unit can provide efficacy data related to residual breathing events and amount of air leak, what it cannot do is provide a measure of sleep quality. There is an urgent need to evaluate the benefit of adding a measure of sleep quality to a CPAP adherence protocol. The project will utlize the gold-standard sleep measurement of polysomnography in the home environment. Project Objectives: The objective of this proposal is to evaluate feasibility and potential efficacy of adding a novel measure of treatment efficacy that facilitates patient-centered, collaborative care for patients with OSA who are prescribed CPAP. The measurement and tracking of sleep quality will be added to our current CPAP interventional program and this information will be fed back to both patients and providers to help inform CPAP management, with the goal of improving CPAP adherence and outcomes. Project Methods: Because it is well-known that adherence patterns are established very early in treatment, our CPAP adherence intervention is designed to provide new CPAP users with education and support they require to get started on CPAP and is focused on two key issues: (1) troubleshooting of problems early in treatment that often derail patients, and (2) discussion, recognition, and tracking of treatment benefits. We have named our standard adherence intervention protocol PC3 which is short for Patient-Centered, Collaborative Care, and is based on our previous work. Objective measurement of sleep quality is a central component of documenting CPAP benefit. The overarching aim of the proposed project is to examine the feasibility and potential effect of adding sleep quality measurement and feedback to PC3 on improving the quality of care, and increasing CPAP adherence to a clinically meaningful level. We have named the enhanced PC3 protocol (which includes sleep quality measurement) as PC3+ to reflect the additional component. The central questions addressed by this study: Does adding an objective measure of sleep quality to an existing CPAP adherence intervention protocol have an effect on the patient's level of CPAP adherence, experience of chronic illness care, and OSA outcomes? To answer these research questions the proposed randomized, controlled trial will compare our Patient-Centered, Collaborative Care adherence intervention (PC3) to the same intervention with the sleep quality measurement added (PC3+).